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    Logic & Programming
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    Math Problem
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Question 1

a) i) The layered architecture acts as a transmission channel during the communication process, its structure is followed during the communication with receiver and sender in a protocol with the help of different devices including routers and switches. A proper way of transmission channel is required for transferring messages to the receiver end. This can be possible with the help of layered architecture in the computer system. This layered architecture according to Zheng and Sicker (2013) helps in offering a layered way that can be used to transmit a signal through a channel. There are three parts making up the overall process of communication and these include sender, receiver and transmission channel. It is within the sequence of sender, transmission channel and receiver that the layered architecture works in facilitating proper transmission of messages from sender to receiver. Switches and Routers work on the layered architecture in doing the task of transmitting messages from receiver to sender. Therefore, during the communication process, this layered model acts as a data transmission channel.

ii) The OSI architecture offers the layered architecture that helps in transmitting data. The layer architecture in the OSI model consists of seven layers which are responsible for the compilation of each step in the data transmission process. Later, OSI model of data transmission was enhanced and this resulted in the TCIP protocol. According to Huang et al. 2014 the TCIP protocol is superior because it has not only satisfied the steps of the communication process but it has also enhanced the quality of data transmission process.

b) There is a close relationship between the physical layered architecture and the physical evidence of information and data being transmitted including the transmission medium and transmission channel. Packet-switching technology aids in the transfer of datagram. The datagram, according to Elias and Ali (2014) is transmitted or taken to the router so that wireless transmission of data packets can be done there. This means that the router will have to get connected to two physical layers. These physical layers are composed of half duplex and full duplex mode that are responsible for enabling datagram transmission through the router. Connected devices in full duplex mode can receive and send datagram consecutively.

At the sender terminal, data encapsulation takes place. Apart from encapsulation, there is also the addition of 2 logical addresses. The responsibility of the Data Link layer is to link the datagram with the destination address in the router. The datagram’s address bits are recorded by the router, which also links them to the destination. The other work of the router is that of decapsulating data packets from the frames for transmission to the destination address. Data decapsulation is done before the data is taken to the upper layer. During this entire process, the physical address changes as the logical address remains the same. The IP address helps in the identification of the destination and unique host devices (Taher, Ghani and Khan 2017). The significance of this phenomenon is that it enhances the security of data transmission through router as well as other wireless devices.

Question 2

a) i) TDM refers to a process that looks like the time division of the data signals in the transmission channel, which has high bandwidth. The time division multiplexing in the transmission channel helps in sustaining the time band of the data transmission signals. According to Robertazzi (2017), the existence of signals with high bandwidth helps because during the channel transmission, the signals will divided into time gaps. When it comes to FDM, there is frequency division multiplexing. This is where frequency is divided into various or different parts. The TDM construction involves or is about time division of signals. TDM in this case helps in allocating time slots in the channel and in constructing the data flow in the same channel. It is easy to divide the high bandwidth signal into time slots. This work is done by demultiplexer and multiplexer.

ii) Low-pass and TDM approach have an advantage of offering better protection against tapping as well as selective interference. They achieve this through coordinate considering that two senders may interfere in case they, at the same time, chose the same frequency. On the other hand, the advantage of the FDM and band-pass approach is that they can work for analog signals as well. Dynamic coordination is not needed in this approach. The disadvantage of this approach, however, is that it has scarcity and is so inflexible that when one channel is idle the other one is busy.

a.i) Latency can be defined as an expression of the amount of time that a packer of data takes moving from one point to another. Process delay, transmission time, queuing time and propagation time constitute the four components of latency. The time it takes a signal to be transmitted from sender to receiver is called the propagation time. Queuing time according to Kurose (2015), refers to the time that a signal takes or waits before it is propagated. Transmission time on the other hand refers to the time that the signal takes to be transmitted through the channel. The processing delay refers to the time that the routers take to check errors in the data packet. The router needs to reduce the process delay time so that the performance of transmission can be enhanced in the channel. When there is large bits, the routers take large process time in checking errors and this delays transmission time meaning that there is need for the reduction of the process delay time.

Question 3

  1. In a low-level protocol, the ARP protocol will be working at layer 2. The ARP protocol in this case will be acting as an interface between OSI network layer and OSI link layer. According to Elias and Ali (2014) the work of ARP is to provide an abstraction between IP address and MAC. This will proved a secure connection with the host devices. The other work of ARP is that it helps in mapping IP address of two hosts simultaneously. However, ARP faces different attacks and some of these attacks are ARP denial of service and ARP spoofing. These attacks result in loss in data bits from message frames.

  2. i) Dataword: 10101100

CRC: 1111.101000

Divisor: 1011

ii) Dataword 1 is 11001100110011

Dataword 2 on the other hand is 110111001101110

Adding Dataword 1 and 2 leads to 1010000110100001

Dataword 3 on the other hand is 1000010000100001

Result is 10010010111000010.

This means that it is the 16-bit internet checksum.

Question 4

a)i) Considering IP address for configuring on router R1.

The first step: R1>enable

The second step: R1#config t

The third step is: R1(config)#int fa0/0

The fourth step: R1 (config-if)#ip address

The fifth step is: R1 (config-if)#bandwidth 1000

The sixth step is: R1 (config-if)#no shutdown

The last step is: R1 (config-if)#exit

ii) Considering IP address for configuring switch

The first step is: Switch (config)#interface vlan 1

The second step is: Switch (config-if)#ip address

The third step is “Switch (config-if)#no shutdown

The last step is: Switch (config-if)#exit

ii) The switch receives the IP addresses from the DHCP server since IP address of Switch is not available in the physical interface as it behaves like a bridge and is not required on the physical interface on switch. This security level of the switch is acquired in the layered communication process.

b) Kurose (2015), claims that telnet refers to a tool in the computers that is used for communication purpose. The main issue that concerns the telnet is the security problems. Telnet in this case offers flexibility and simplicity in the protocols that are responsible for causing loopholes in security protocols. This makes telnet protocols to be prone to cyber attacks. The fact that data is sent in a text format also means that the data is less secured.

c) IPCP is an abbreviation for Internet Protocol Control protocol and it helps when it comes to the configuration of a security internet protocol so that data can be secured over internet. According to Robertazzi (2017) IPCP helps in establishing a point-to-point connection using protocol link. Included in the IPCP are a data bit and frame that is transferred over the network. The data bits in this case resemble the PPP protocol system. The transmission of data packets over the network is done in an encrypted form so that the data is secured.


Brandwine, E.J. and Hill, P.J., Amazon Technologies, Inc., 2016. Providing virtual networking functionality for managed computer networks. U.S. Patent Application 15/011,302.

Elias, M.S. and Ali, A.Z.M., 2014. Survey on the challenges faced by the lecturers in using packet tracer simulation in computer networking course. Procedia-Social and Behavioral Sciences131, pp.11-15.

Huang, T.Y., Jeyakumar, V., Lantz, B., Feamster, N., Winstein, K. and Sivaraman, A., 2014. Teaching computer networking with mininet. In ACM SIGCOMM.

Kurose, J.F., 2015. Computer networking: A top-down approach featuring the internet, 3/E. Pearson Education India.

Robertazzi, T.G., 2017. Wireless networks. In Introduction to Computer Networking (pp. 35-60). Springer International Publishing.

Robertazzi, T.G., 2017. Introduction to Computer Networking. Springer.

Taher, M.T., Ghani, U. and Khan, A.S., 2017, June. A Comparative Study for Determining the Impact of Simulation-based, Hands-on and Feedback Mechanisms on Students’ Learning in Engineering Technology and Computer Networking Programs. In 2017 ASEE Annual Conference & Exposition.

Zheng, C. and Sicker, D.C., 2013. A survey on biologically inspired algorithms for computer networking. IEEE Communications Surveys & Tutorials15(3), pp.1160-1191.